Cal. Rev. & Tax. Code § 3795

The agreement shall be submitted to the Controller. If he or she does not approve the agreement, he or she shall return the agreement to each party with a statement of his or her objections to it, and thereafter a new or modified agreement may be made. If the Controller approves the agreement, he or she shall sign the executed copy, return the signed agreement to the tax collector, and keep a copy on file in his or her office.